The present application relates to an optical disc recording and reproducing apparatus and an optical disc recording and reproducing method which record data onto an optical disc and reproduce recorded data and, particularly, to an optical disc recording and reproducing apparatus and an optical disc recording and reproducing method which record identification data such as a barcode onto an optical disc and reproduce recorded identification data, for example.
A technique of recording barcode form data onto a burst cutting area (BCA) in the innermost periphery of an optical disc DK has been used for the purpose of illegal copy protection for optical discs. Identification information such as a serial number or an identification number (ID) is recorded in the barcode form data, and the use of such information in the management of optical discs prevents illegal copy of the optical discs.
The barcode form data (which is hereinafter referred to as a BCA code) is data that is composed of differently spaced bars. The data is obtained by converting (encoding) the original data of a BCA code (hereinafter referred to as BCA data), which is identification information such as a serial number or an identification number, by a prescribed data conversion scheme.
A BCA code is recorded as follows. Firstly, BCA data is converted (encoded) into a signal with different pulse intervals by a prescribed data conversion scheme. The signal is then converted into a signal which is synchronized with the rotation speed of an optical disc, and a pulse laser beam which is generated based on the converted signal and modulated between a high level and a low level is irradiated onto the BCA of the optical disc. In this case, the laser beam generally forms an oval-shaped optical spot on the BCA of the optical disc. The optical spot is moved to the rotative direction and the radial direction by a rotational mechanism of the optical disc and a feeding mechanism of the optical head or the optical disc, so that the laser beam is irradiated onto the substantially entire area of the BCA. The portion where the high-level laser beam is irradiated is subject to change such as melting of the surface of the optical disc or alteration of a recording layer. The changed portion serves as a bar of a BCA code. Therefore, the irradiation of the pulse laser beam modulated between a high level and a low level onto the BCA forms a portion where a surface is changed and a portion where a surface is not changed, and a BCA code which is composed of a plurality of differently spaced bars is formed (recorded) by a difference between the two portions.
If the reproducing laser beam is irradiated onto the recorded BCA code which has been recorded as above, a signal with different pulse intervals is obtained from the reflected light. The signal is converted into a binary signal and decoded, thereby obtaining identification information such as a serial number or an identification number, which is BCA data. Thus, an optical disc can be managed based on the decoded identification information.
A specific method of recording the BCA code is described in Japanese Unexamined Patent Application Publication No. 2007-035087, for example.
The optical disc on which the BCA code is not properly recorded is discarded as a defective. Accordingly, original data (hereinafter referred to as BCA data) which forms the BCA code that is written on the discarded optical disc is also discarded. Therefore, if the BCA data of manufactured optical discs are managed using sequence numbers, the sequence number that is assigned to the BCA data of the discarded optical disc is a missing number, which hampers the subsequent product management.
As an apparatus to address such an issue, a BCA recording and reproducing apparatus which includes a means of recording BCA data and a means of reproducing BCA data is described in Japanese Unexamined Patent Application Publication No. 10-289486. The BCA recording and reproducing apparatus reproduces BCA data which is recorded on an optical disc immediately after the BCA data is recorded and then verifies the reproduced data against recording data, thereby determining whether the BCA data is properly recorded. If the BCA data is not properly recorded, the apparatus discards the relevant optical disc and records the same BCA data onto the next optical disc. The BCA data in itself is thereby not discarded, which prevents the occurrence of the issue described above.